Progress 05/15/08 to 01/14/09
Outputs
OUTPUTS: One of the biggest obstacles identified by stakeholders is the cost of SPLAT CLM. The cost is based on the manufacturing of SPLAT and the synthesis of the pheromone components. Our largest cost is associated with the synthesis of the triene. In response to this we did a large, 25 treatment, field trial to determine the effectiveness of CLM disruption in commercial Florida orchards using the complete and incomplete blends. All these data have been shared with growers in Florida and California, in field days and citrus growers association meetings. In Phase II we will be working towards an more efficient and economic formulation for the CLM. PARTICIPANTS: We worked intensively with Dr. Lukasz Stelinski's group, of Lake Alfred, University of Florida; and Dr. Stephen L. Lapointe, Research Entomologist USDA, ARS, U.S. Horticultural Research Lab. Fort Pierce, Florida. TARGET AUDIENCES: All our data and findings so far have been shared with growers of Florida and California, either in direct conversations, in field days, farm visits and citrus growers (association) meetings. PROJECT MODIFICATIONS: NONE
Impacts
The ratio of female sex pheromone components (3:1 triene:diene) as present in the pheromone glands of female P. citrella was a potent attractant in the field. Attraction to baited traps declined markedly as the ratio departed from this ratio with little interaction between proportion and amount. The response surface generated in the disruption trial, however, was markedly different compared with the attraction trial. The straight line described by the response surface corresponding to the highest pheromone concentration and X1-X2 axis visually demonstrates that trap shutdown increased in direct proportion to the concentration of the triene component with no synergistic or antagonistic blending effects between the diene and the triene. This lack of blending suggests that an unnatural ratio consisting of one or the other of the single components could be as effective as the natural blend for mating disruption. We tested the hypothesis in a large, replicated, 25 treatment, field trial. The lack of blending together with the general lack of congruence between the response surfaces generated for attraction and disruption (trap shutdown) support the conclusion of Stelinski et al. 2007 that disruption in this species is a noncompetitive phenomenon. If disruption were competitive, congruence between the response surfaces for attraction and disruption would be expected. In phase I, we were able to determine the effectiveness in promoting mating disruption of CLM of the different SPLAT formulations, but we weren't able to determine how long the effect lasted because we had to stop our field experiment after 26 days, and another experiment at 80 days. We will determine in Phase II how long our attract and kill and mating disruption formulations last in the field. Furthermore, in order facilitate the application of SPLAT CLM to orchards, we developed, along with colleagues at Michigan State University (Rufus Isaacs, Luis Teixeira, and Keith Mason), has created a mechanical applicator for SPLAT application deemed the "SPLAT-o-Gator." This system allows growers to apply SPLAT CLM to two rows of trees at 10 miles per hour, greatly facilitating the deployment of the product in the field. We will perform larger field trials using the mechanical applicator in Phase II.
Publications
- Stelinski, L.L., J.R. Miller, and M.E. Rogers. 2008. Mating disruption of citrus leafminer mediated by a non-competitive mechanism at a remarkably low pheromone release rate. Journal of Chemical Ecology. 34: 1107-1113.
- Stelinski, L.L. and M.E. Rogers. 2008. Factors affecting captures of male citrus leafminer, Phyllocnistis citrella, in pheromone-baited traps. Journal of Applied Entomology. 132: 143-150.
- Gut, L.J., L.L. Stelinski, D.R. Thompson, and J.R. Miller. 2004. Behavior modifying chemicals: prospects and constraints. In: O Koul, G.S. Dhaliwal, and G. Cuperus (eds.) Integrated Pest Management: Potential, Constraints, and Challenges. CABI Press. N.Y., pp. 73-121. pp. 261-311.
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